Who undermines the nuclear treaty

The nuclear non-proliferation treaty (NPT), the agreement that has helped prevent the spread of nuclear weapons, is looking increasingly fragile.

Diplomats from some 190 countries gather in New York today for a month-long review of the accord signed in 1968. Review conferences take place every five years and with each one, the sense of frustration and impatience just piles up.

In the bargain struck under the NPT, the five recognised nuclear states - the US, Russia, China, France and Britain - promised to gradually eliminate their nukes and to allow non-nuclear states access to peaceful nuclear energy. In return, the have-nots agreed not go nuclear. Over the years, all countries except India, Pakistan and Israel have signed up to the treaty.

This year's conference is set to be dominated by a clash between the US and Iran. Washington accuses Tehran of seeking to develop nuclear weapons in violation of its NPT obligations and has been working, so far unsuccessfully, to bring Iran to the UN security council for possible sanctions.

North Korea is another problem, although Pyongyang will not be there. North Korea has withdrawn from the NPT and has thumbed its nose at everyone by telling the world it has nuclear weapons. The US will seek to browbeat both Iran and North Korea, but Washington itself can expect criticism for flouting the spirit of the treaty.

Some of the Bush administration's harshest critics have come from the US itself. Robert McNamara, the Vietnam-era US defence secretary, wrote in the current edition of Foreign Policy magazine: "I would characterise current US nuclear weapons policy as immoral, illegal, militarily unnecessary and dreadfully dangerous."

Former president Jimmy Carter has also harshly criticised the White House.

"While claiming to be protecting the world from proliferation threats in Iraq, Libya, Iran and North Korea, American leaders not only have abandoned existing treaty restraints but also have asserted plans to test and develop new weapons," he said last month.

Carter was referring to the nuclear "bunker buster", aimed at destroying targets buried deep underground. The administration has asked again Congress for money to study the feasibility of such a bomb, after being rebuffed last year.

The don't haves are also bristling at US plans to replace its existing nuclear stockpile. A senior government official this month told Congress the administration believed it could develop a more reliable stockpile that was better suited to future threats but which would not require nuclear testing. As long as the US is seen as bending the NPT to suit its own needs, it can only undercut its own efforts to browbeat "rogue" states such as Iran and North Korea.